In a known process for the production of sterilized and packed liquid food, for instance berry juice, cream, sauce, soup, etc., the food is first sterilized in a sterilizer, after which it is conveyed in conduits to an aseptic packing machine, if necessary via an aseptic intermediate storing container. During the process, the sterility of the food must be confirmed by regularly testing the bacterial content of the food. One way of accomplishing such tests is by testing samples of the contents of the filled packages. Another way is to draw off minor quantities of food for testing via valves, which can be arranged at different places along the process line. The latter method is applied in practice by keeping an open container in the vicinity of a valve, while the latter is opened for a short period of time. Usually there is an arrangement which creates an approximately sterile environment around the valve.
A drawback with the first way of testing is that when packages with unsterile content are discovered, it is impossible to directly state where in the process defects have arisen. Locating faults will therefore be time-consuming and expensive. A drawback with the latter method is that the valves often mechanically affect the quantity of food drawn off in an undesirable way. Often the food contains delicate coarse particles such as whole berries, beans, carrots in the form of cubes etc. At times these particles partly clog an open valve, so that the food is filtered when passing through the valve. Of course, also such coarse particles should be included in the sterility test. However, if a valve is opened sufficiently to permit passage of the coarse particles the flow of food through the valve into the relatively small open receptacle normally used can be unacceptably great, since the liquid food is under a certain overpressure in the process apparatus. In certain cases the particles can be mashed when passing through the valve, which means a change of the consistency of the food. Test samples obtained through valves therefore are often not completely representative of the food in the process apparatus. Further, it is difficult to accomplish sampling of food via valves during aseptic conditions. Thus, the samples can be infected by bacteria during the sampling, which of course will give a wrong indication of the condition of the food treated in the process.
The object of the present invention is to avoid the above described drawbacks with the known ways of testing the bacteria content of sterilized liquid food by providing a new method, which admits aseptic transfer of a sample of a limited quantity of food from an optional place in a process apparatus to a sampling receptacle without the food being changed and which in addition admits aseptic transfer of relatively coarse particles in the food to the sampling receptacle. A further object of the present invention is to provide a simple sampling device for accomplishing such a method.